I really enjoyed the game, and the music make the experience feel emotional.
The environment feels nice, with gems and shiny details :D
I like that you added a timer so it gives possibility for speedruns, or just improving.
I had 2 issues that occurred a couple of times:
-When switching world, sometimes I got stuck in the wall, solution was usually to fall and die, then try again. I like that you added a reset button to mitigate it.
-Sometimes when jumping up to thin platforms, I would end up walking inside it instead of on top of it.
-Not sure if it's by design that ghost guy can climb up walls if you spam jump and walk towards it, but I abused that a bit xD
Really nice game, would love to see it polished some more!